Field of the Invention
The present invention relates to information processing technology, and more specifically relates to technology for determining a communication port of a device connected to a network.
Description of the Related Art
Among methods for searching from a computer for devices such as image forming devices connected to a network, and installing on the computer a device driver compatible with a device specified by the search, the following sort of method is widely known. That is, a method is known in which a printer driver or a scanner driver is associated with a communication port compatible with a predetermined network protocol.
In the past, a device search protocol came to be independently developed by the manufacturer who developed a device. However, recently, as a standard function of an OS, it has become possible to search for devices compatible with a UPnP protocol and install a device driver, associated with a communication port compatible with that protocol. Note that OS is an abbreviation for Operating System, and UPnP is an abbreviation for Universal Plug and Play.
Devices compatible with both a proprietary device search protocol and an OS-standard device search protocol have become more common, but there is a possibility that a device cannot be detected depending on a network state or a device state. In Japanese Patent No. 4877127, a method is disclosed in which, when a printer was detected using a first protocol but was not detected using a second protocol having a higher priority, the printer is searched for again using the second protocol, and thus a device compatible with a specified protocol is reliably detected.
In an office environment for example, there are many situations where devices are installed on different subnets, and the ability to reliably and stably use the devices installed on different subnets is desired.
However, there are cases where a device search by the OS-standard UPnP protocol is limited to a search within the same subnet, and there are cases where devices installed on different subnets cannot be detected.
Also, a device becomes usable for the first time after successfully associating a device driver with a communication port compatible with a network protocol. However, when a user installs a device driver, it is necessary for the user him/herself to determine whether or not the computer and the device exist within the same subnet, and determine a communication port according to the result of that determination. For example, when the user desires to use a communication port employing an OS-standard protocol, it is necessary for the user him/herself to check whether or not the computer and the device exist within the same subnet. Also, it is necessary for the user him/herself to determine a communication port compatible with an OS-standard protocol in a case where the computer and the device exist within the same subnet, and determine a communication port compatible with a separate protocol capable of detecting a device that exists on a different subnet than the computer in a case where the computer and the device do not exist within the same subnet.